Subject: bug#78841: reftex-get-bibfile-list fails to detect biblatex if there's no buffer for the main file

From: Arash Esbati <[email-masked]>
Date: Wed, 25 Jun 2025 09:15:18 +0200

Tim Ruffing <[email-masked]> writes:

> I've tested this, and this works in this specific case.

Thanks.

> But are you really suggesting this as a fix?

The way I see it this is a bug in latexenc.el which we should try to fix
anyway.  That would basically improve the current state.

> I feel this is building a hack on top of another.

Maybe, OTOH, mule-conf.el which adds

  ("\\.\\(tex\\|ltx\\|dtx\\|drv\\)\\'" . latexenc-find-file-coding-system)

to `file-coding-system-alist' is pre-loaded in Emacs.  So I would argue
we're relying on Emacs' default behavior here.  And if people remove
that entry, they should know what they're doing.

> If AUCTeX needs the master file to be open, then it just should open
> it and not rely on latexenc to open it.

Will take a closer look at this later, but remember that RefTeX should
also work without AUCTeX, so this point isn't much relevant.

> Your change doesn't solve the issue if any of the following happens:
>  * latexenc-dont-use-TeX-master-flag is t
>  * latexenc will be removed or changed in the future
>  * the \addbibresource commands is not in the same file as
>    \usepackage{biblatex}, see the test case in the attached zip.
>    (Again, extract it to some folder, cd into the folder with the tex
>    files, and run `emacs --init-directory=. --no-splash`)

I see your point, but I think these are sort of corner cases, given how
many times they were raised in the past.  I currently don't have the
time and energy to solve this issue in a way which can deal with all the
cases above, but I'll be happy to review and install such a change.
Patches are welcome.

Best, Arash